UBUNTU-CVE-2026-23455
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() In DecodeQ931(), the UserUserIE code path reads a 16-bit length from the packet, then decrements it by 1 to skip the protocol discriminator byte before passing it to DecodeH323_UserInformation(). If the encoded length is 0, the decrement wraps to -1, which is then passed as a large value to the decoder, leading to an out-of-bounds read. Add a check to ensure len is positive after the decrement.
CVSS Metrics
- v3.1•CRITICAL•Score: 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Affected Systems
- ubuntu•linux
all | all | all | all
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
all | all | all | all
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.15
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.4
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
all
- ubuntu•linux-aws-6.17
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
all
- ubuntu•linux-aws-fips
all
- ubuntu•linux-aws-hwe
all
- ubuntu•linux-azure
all | all | all | all | all
- ubuntu•linux-azure-4.15
all
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.15
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.4
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.14
all
- ubuntu•linux-azure-6.17
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all | all | all
- ubuntu•linux-azure-fde-5.15
all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.14
all
- ubuntu•linux-azure-fde-6.17
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fde-6.8
all
- ubuntu•linux-azure-fips
all
- ubuntu•linux-azure-nvidia
all
- ubuntu•linux-azure-nvidia-6.14
all
- ubuntu•linux-bluefield
all | all
- ubuntu•linux-fips
all
- ubuntu•linux-gcp
all | all | all | all | all
- ubuntu•linux-gcp-4.15
all
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
Showing first 50 affected entries in server-rendered view.
References (9)
- https://ubuntu.com/security/CVE-2026-23455
- https://www.cve.org/CVERecord?id=CVE-2026-23455
- https://git.kernel.org/linus/f173d0f4c0f689173f8cdac79991043a4a89bf66
- https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4
- https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111
- https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8
- https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b
- https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66
- https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60